Is there an advantage of having spark plugs that need gaping versus the lazy non-gapping ones?

Basically, one of my (NGK gapped) plugs weren't seated right and began ticking until I bolted it down. After that my car started misfiring on occastion. I went to walmart and bought some Bosch (Platinum 2's i believe) Non-gapped plugs to switch that one out to see if it would fix the problem. Which it did I'm just wondering what's the point of buying plugs that you have to keep gapped correctly versus buying a 'lazy' set.

Also, will it harm my car if I have 1 different plug than the rest? lol. I just switched the one and kept the other NGK's in there. "If it aint broke, don't fix it"